The Key Parameter Visualization Tool (KPVT), developed at the ISTP Science Planning and Operations Facility (SPOF), is a generic software package to visualize the key parameter data produced from ISTP missions, interactively and simultaneously. The tool is designed to facilitate correlative displays of ISTP data, and thus the selection of candidate events, data quality control.

The software, written in IDL, includes a graphical user interface, and runs on many platforms including multiple UNIX workstations, VAX/Open VMS, PC/Windows 95, and Macintosh. The full package of the tool including the source code, installation instructions, and other important materials can be obtained via anonymous FTP.

Version 2.1 of the KPVT will be publicly available to the ISTP community starting 12-2-1996. It supports various plot types such as time series, spectrograms, and images. The user interface is flexible and easy to use. The basic requirement for users is to select the data to be displayed. For new data selections, the plot will be generated automatically with default settings. Many options are available for users to customize the plots if desired. All data and plot parameters can be saved into a Plot File template and retrieved later for reuse.

• System Setup: quick and flexible access to a user's local environment.

  The directory paths of a user's local database and print commands for various printing facilities can be interactively stored in the tool's system for easy access to files and printers. User options such as variable choices for the default color table, file path, printer, and the size of the plot display window on the computer screen are also available.

• Data Selection: flexible data selection procedures to accommodate versatile choices for users.

  Once a desired file and key parameter are selected, the KPVT will analytically determine and provide all the possible selection choices for a user to select. For non-image data, the data can be plotted in multiple panels up to a maximum of 15 panels. Each panel may contain one or two variables. Data may be selected from multiple files, corresponding to one or multiple investigations. For image data, only one type of image can be selected at a time.

• Plot Control: flexibility and capabilities ranging from interactive plot manipulation to on-line custom plot making.

  Many options are available for plot manipulation. The plot controls panel provides access to the most frequently used IDL plotting settings. All user-defined plot parameters can be saved into a Plot File and retrieved later for reuse.

  For visualization of images, two different displays are available and the options also include color scale, color table, and plot format manipulations.

  For non-image displays, various plot characteristics can be customized, including:

  • overall plot settings such as font size, thickness of characters, and the style of plot panels.
  • axis settings such that every axis in every plot panel can be customized independently. The options consist of labels, character size, scale ranges, scalings, tick marks, the length of tick marks (inwards, outwards, or a grid), color bar scales, etc. An interface is also provided for easy time-range adjustments.
  • ability to save customized plot styles in the users' individual preferred setting.
  • plot layout, panel locations and spacing between panels that a user can specify.
  • user-specified color bars.
  • adding custom vertical or horizontal lines to the plots such as a zero line or a pair of vertical guide lines. Each panel can have 10 line additions in either orientation.
  • annotating the plots with text in user-preferred styles. The tool allows 30 text additions to the plot.

  The tool supports various output formats, including PostScript files for hardcopy printing, as well as GIF files for easy import into world wide web documents.

• Plot Files and Viewing Loops: painless, cost-effective and efficient approaches to interactive data visualization over huge and rich collections of ISTP key Parameters on a regular basis.

  Once a user has decided what to plot and how to plot, all the necessary data and plot parameters can be saved into a Plot File, a reusable plotting template. At a later time, a user only needs to open a desired Plot File and select the appropriate data files. The data will be immediately displayed according to the preset preferences. After a Plot File is created, a user doesn't need to repeat the interactive selections over the same data and plot parameters again. A user can take advantage of viewing loops to continuously view different data files with the same set of data selections in preferred plot formats.

• Browser:

  Any GIF or ASCII file can be selected for display with the hardcopy option.

• Modularized Tools:

  A tool for generating CDFskeleton tables is currently available.

• On-Line Help:

  The on-line help is available to guide users through step-by-step instructions. Plot examples and tutorial instructions are also provided.

The following are example screen shots and the step-by-step instructions for creating them.

Example	Screen shot	Instructions
Line Plot
Line Plot and Spectrograms
Line Plot
Line Plot and Spectrograms
The next four examples are applications of Plot File and Viewing Loop
Day Sequence 1
Day Sequence 2
Day Sequence 3
Day Sequence 4
Line Plot
Line Plot
Images
Image
Images
Images

Syau-Yun Hsieh, 
ISTP Science Planning and Operations Facility 
E-mail: xrswh@pwg.gsfc.nasa.gov
Phone: (301) 286-4981       Fax: (301) 286-1683